1. Field of the Invention
The present invention relates to a filter attachment machine for a filter cigarette manufacturing system, and more particularly, to a tip paper cutting apparatus incorporated in the filter attachment machine.
2. Description of the Related Art
In recent years tobacco with mild taste has been in demand. To meet the demand, filter cigarettes each having a filter at one end of a cigarette are on the market. Filters are attached to respective cigarettes in a filter attachment machine of a cigarette manufacturing system, by wrapping a piece of tip paper around a cigarette and a filter. To this end, typically a wrapping section provided in the filter attachment machine is supplied with filter plugs each interposed between two cigarettes, as well as pieces of tip paper applied with paste.
In connection with the supply of pieces of tip paper applied with paste, the filter attachment machine has a transport path for guiding the tip paper unrolled from a paper roll to the wrapping section, and a paste applicator is arranged so as to face the transport path for applying paste to one side of the tip paper. On the downstream side of the paste applicator, a cutting apparatus is arranged for cutting the tip paper, which has been applied with paste, into pieces with a predetermined length. Also, a heater is arranged on the upstream side of the paste applicator for heating the one side of the tip paper to be applied with paste prior to the paste applying step, and a predrier is arranged on the downstream side of the paste applicator for heating the opposite side, or the non-paste side, of the tip paper to dry the paste applied to the tip paper by means of heat conducted to the paste from the tip paper.
The pieces of tip paper cut by the cutting apparatus are supplied to the wrapping section, where each piece of tip paper is wrapped around two cigarettes with a filter plug therebetween. Double-length filter cigarettes obtained in this manner, each connected by a piece of tip paper, are cut in the center of the filter plug, thereby obtaining individual filter cigarettes.
The cutting apparatus mentioned above generally comprises a receiving drum for attracting the tip paper by means of negative pressure, and a bladed drum facing the receiving drum and rotated in a direction opposite to that of the receiving drum. The bladed drum has cutting blades mounted thereon close to the receiving drum. The tip paper applied with paste is fed in between the receiving drum and the bladed drum, with the paste-applied surface thereof facing the bladed drum, and cut into pieces by the cutting blades as the two drums rotate.
Accordingly, when the tip paper is cut, the cutting blades come into contact with the paste-applied surface of the tip paper, whereas the paste applied to the tip paper has considerable adhesive strength, though it has been predried in the preceding step. Thus, after repeated cutting operation, the cutting blades are encrusted with paste and the cutting quality thereof lowers. To eliminate this, for example, a repellent liquid such as olive oil is sprayed on the brush of a rotatable brush roller arranged in the vicinity of the bladed drum, and olive oil is applied to the cutting blades by means of the brush.
However, since olive oil scatters from the brush due to the centrifugal force caused by rotation of the brush roller, the brush cannot retain sufficient olive oil, and thus the cutting blades may be insufficiently applied with olive oil. In such cases, incrustation of paste cannot be satisfactorily prevented, lowering the cutting quality of the blades. If the tip paper cutting becomes defective due to the lowering of the cutting quality of the blades, the tip paper is consumed wastefully. Also, to remove the paste incrustation from the cutting blades, the operation of the cigarette manufacturing system must be stopped, lowering the productivity.
To eliminate the inconvenience, a greater amount of olive oil may be sprayed. In this case, however, the amount of olive oil scattered from the brush also greatly increases, which leads to increased consumption of olive oil. Since olive oil is expensive, the cost of manufacturing cigarettes also increases. Further, olive oil scattered from the brush to surrounding parts damages the quality of cigarette products, and also brings about even lower productivity because the parts surrounding the brush must be cleaned more frequently. This disadvantage is noticeable particularly in a high-speed cigarette manufacturing system since the brush roller rotates at high speed.